Genotyping Study of Scedosporium apiospermum Isolates from Patients with Cystic Fibrosis

Abstract

Usually a saprophyte, Scedosporium apiospermum often colonizes the respiratory tracts of patients with cystic fibrosis (CF). In order to improve our understanding of the molecular epidemiology of the airway colonization, 129 sequential and multiple isolates collected from January 1998 to March 1999 from nine CF patients monitored in three hospitals in France were typed by random amplification of polymorphic DNA with primers GC70, UBC-701, and UBC-703. Among these primers, UBC-703 was the most discriminating, allowing the differentiation of 14 genotypes. Combining the results obtained with this three-primer set resulted in the differentiation of 16 genotypes. No common genotype was found among the different patients, and no clustering according to geographic origin of the isolates was seen. In addition, five of the patients were colonized by a single genotype. The others usually exhibited a predominant genotype accompanied by one or two others, which were found occasionally and were genetically close to the predominant genotype. Thus, our study demonstrates the persistence of the fungus despite antifungal treatments and therefore reinforces the need for the development of new antifungals that are more efficient against this species.

Molecular Typing of AustralianScedosporiumIsolates Showing Genetic Variability and NumerousS. aurantiacum

“…This diversity is generally consistent with the high degree of polymorphism (15-20 genotypes) previously found (10,20,32). In contrast, genetic variation was lowest (28%) among the S. aurantiacum isolates (online Appendix Figure 1; Figure 3).…”

“…Molecular typing techniques now provide the means to elucidate the epidemiology of Scedosporium infections and to investigate potential case clusters (16,18,19). Strains recovered from patients with cystic fi brosis have demonstrated a high degree of genetic variability (10,20), although a single genetic profi le predominated in 1 study (8). The degree of genetic variation within S. prolifi cans is more controversial.…”

“…aurantiacum S. apiospermum infections occur worldwide, ranging from localized mycetomas to deep-seated disease such as cerebral abscesses (6,7). This species also colonizes the respiratory tract of ≈10% of patients with cystic fi brosis and chronic suppurative lung disease (8)(9)(10). On the basis of genetic data, a new species, S. aurantiacum, was proposed for a subset of isolates previously identifi ed as S. apiospermum (11).…”

Molecular Phylogeny of the Pseudallescheria boydii Species Complex: Proposal of Two New Species

“…Rainer et al (16) reported the existence of five different small-subunit rRNA gene sequence lengths. Random amplified polymorphic DNA studies also demonstrated that numerous and very different genotypes can be found (7). Other authors have reported considerable differences with respect to growth and sporulation (4,5,9).…”

Diagnosis of Invasive Fungal Infections – Current Limitations of Classical and New Diagnostic Methods

“…In general, assays targeting multicopy genes have better detection limits than those targeting single copy genes. 135 Although PCR may become a diagnostic modality to identify Mucorales, [136][137][138] Scedosporium, [139][140][141] and several other fungi, [142][143][144][145][146][147][148][149][150][151] no commercial test is available to date. These techniques hold promise, but they are not yet standardised or readily available in most clinical laboratories.…”